Increase in Laccases Production by an Improved Strain of White Rot Fungi Pycnoporus cinnabarinus with an Additional Improvident in the Production Medium

Several microorganisms including fungi and bacteria produce the most important industrially applicable enzyme “laccases”. The present work was aimed to apply mutagenesis on the test fungus Pycnoporus cinnabarinus for enhancement of the enzyme production and further increase in the production by supplying an improvident in the media. The efficiency of Laccases production by the wild fungal strains Pycnoporus cinnabarinus was investigated by the treatment with physical mutagen [ultraviolet radiation (UV) and X-rays] and chemical mutagens [Ethidium bromide, Colchicine and Hydrogen peroxide]. The effect of X-rays showed an increase in production with increasing exposure (Max. at 8 sec.). Beyond 8 seconds there was a decrease in production. UV irradiation influenced reducing the enzyme production and the maximum dosage is lethal to the fungus. Among the three chemical mutagens, hydrogen peroxide was found to have lethal effects to the fungus and low enzyme production even in minimum concentrations. Colchicine and Ethidium bromide showed an increase in enzyme production with increasing concentrations (Max. at 4 and 7 g respectively). The improved strain of Pycnoporus cinnabarinus showed a 15% of increase in the yield. The increase in production of laccases in a cheap production medium formulated by using agricultural and industrial wastes may be beneficial industrially when compared to the other costly conventional media. Further, mutants obtained by protoplast fusion resulted in even more production. Since ancient times, agricultural and industrial wastes have been used for production of laccases by Basidiomycetes in higher quantity, but the usage of such wastes is still not up to the mark. In this study, Ghee residue (Dairy waste) and wheat bran (agricultural waste) in the laccases production medium (Potato dextrose broth) which is cheaper and efficient when compared to the costly chemical based conventional media with an improved strain of Pycnoporus cinnabarinus (KX8, Accession number 56259) obtained by physical or chemical mutagenesis followed by intraspecific protoplast fusion found to be beneficial. In vitro bioassay of the parental P.cinnabarinus (154.65U/ml/min), its best mutant (165.219U/ml/min) and fusant (176.14U/ml/min) indicated a gradual increase in production of laccases by 17.59%. It was purified using ammonium sulphate precipitation, dialysis, and anion exchange chromatography, yielding 23.86%. Thus, intraspecific protoplast fusion techniques can be employed to develop superior hybrid strains of laccases producing fungi as effective tools for increasing industrial productivity.